class  JiSQ():
    def jia(self,a,b):
        if isinstance(a,(int,float)) and isinstance(b,(int,float)):
            c=a+b
            if isinstance(c,float):
                c=round(c,2)
                return c
            else:
                return c
        elif a=='' or a is None:
            return 'a不能为空'
        elif b == '' or b is None:
            return 'b不能为空'
        else:
            return '非法输入'

    def jian(self,a,b):
        if isinstance(a, (int, float)) and isinstance(b, (int, float)):
            c = a - b
            if isinstance(c, float):
                c = round(c, 2)
                return c
            else:
                return c
        elif a == '' or a is None:
            return 'a不能为空'
        elif b == '' or b is None:
            return 'b不能为空'
        else:
            return '非法输入'

    def cheng(self,a,b):
        if isinstance(a, (int, float)) and isinstance(b, (int, float)):
            c = a * b
            if isinstance(c, float):
                c = round(c, 2)
                return c
            else:
                return c
        elif a == '' or a is None:
            return 'a不能为空'
        elif b == '' or b is None:
            return 'b不能为空'
        else:
            return '非法输入'

    def chu(self,a,b):
        if isinstance(a, (int, float)) and isinstance(b, (int, float)):
            if b ==0:
                return '除数不能为0'
            c = a / b
            c = round(c, 2)
            return c

        elif a == '' or a is None:
            return 'a不能为空'
        elif b == '' or b is None:
            return 'b不能为空'
        else:
            return '非法输入'



d=JiSQ